MOSFET device fabrication method capable of allowing application of self-aligned contact process while maintaining metal gate to have uniform thickness

A method for fabricating a MOSFET device, the method comprising:

• forming a sacrificial gate structure on an active region of a substrate;
• forming source and regions in the substrate on both sides of the sacrificial gate in the active region;
• depositing an interlayer insulating film on the active region of the substrate and on the sacrificial gate structure;
• polishing the interlayer insulating film exposing the sacrificial gate structure;
• removing the sacrificial gate structure forming a groove such that spacers define sides of the groove and the substrate is exposed within the groove;
• depositing a gate insulating film in the groove such that the groove is not completely filled;
• forming a metal gate by depositing a metal film in a remainder of the groove;
• and
• forming a metal oxide on the metal gate.

A MOSFET device, comprising:

• a substrate having an active region;
• a metal gate formed over the substrate within the active region;
• a metal oxide self-aligned contact (SAC) barrier film at a top of the metal gate;
• and
• source and drain regions formed in the substrate on both sides of the metal gate.